English speakers have been calling white liquids “milk” since Old English. But please don’t drink spurge milk (i.e. its white, latex-like sap), since it’s poisonous:

Wið weartan genim þysse ylcan wyrte [sc. spurge's] meolc & clufþungan wos, do to þære weartan. 
Pseudo-Apuleius' Herbarium

“With warts, take the wort (spurge’s) milk & clove-tongues ooze, apply to the warts”

Another pretty old use of the word refers to milk of fish (now called milt). You can eat this, but it’s fish semen:

When þe femele [fish] leggeþ eyren oþer pisen, þe male cometh aftir and shedith his mylke vpon þe eyren and al..þat ben y-touched wiþ þe mylk of þe male shal be ffysshe.
(a1398) Trev.Barth.

From about the same time we start seeing the types of milks you mention in the question:

Cawdel of Almand mylk. Take Almandes blanched and drawe hem up with wyne, [etc.].
(a1399) Form Cury

For more examples refer to the MED.

Another thing worth mentioning is the Milky Way. You should not attempt to drink the Milky Way either. The expressions “milky circle” and “galaxy” are older (Bartholomaeus Anglicus' De Proprietatibus Rerum (translation), 1398) but ultimately those expressions were said in Greek or Latin well before the English:

• Hellenistic Greek γαλαξίας (“galaxy”)
• Ancient Greek γάλα “gála” meaning milk, milky sap, or the Milky Way
• Classical Latin lactea via (milky way)
• Cicero lacteus orbis (milky circle)
• Pliny lacteus circulus (milky circle)

English speakers have been calling white liquids “milk” since Old English. But please don’t drink spurge milk (i.e. its white, latex-like sap), since it’s poisonous:

Wið weartan genim þysse ylcan wyrte [sc. spurge's] meolc & clufþungan wos, do to þære weartan. 
Pseudo-Apuleius' Herbarium

“With warts, take the wort (spurge’s) milk & clove-tongues ooze, apply to the warts”

Another pretty old use of the word refers to milk of fish (now called milt). You can eat this, but it’s fish semen:

When þe femele [fish] leggeþ eyren oþer pisen, þe male cometh aftir and shedith his mylke vpon þe eyren and al..þat ben y-touched wiþ þe mylk of þe male shal be ffysshe.
(a1398) Trev.Barth.

From about the same time we start seeing the types of milks you mention in the question:

Cawdel of Almand mylk. Take Almandes blanched and drawe hem up with wyne, [etc.].
(a1399) Form Cury

For more examples refer to the MED.

Another thing worth mentioning is the Milky Way, which was named after its milk-like appearance. You should not attempt to drink the Milky Way though. The expressions “milky circle” and “galaxy” are older (Bartholomaeus Anglicus' De Proprietatibus Rerum (translation), 1398) but ultimately those expressions were said in Greek or Latin well before the English:

• Hellenistic Greek γαλαξίας (“galaxy”)
• Ancient Greek γάλα “gála” meaning milk, milky sap, or the Milky Way
• Classical Latin lactea via (milky way)
• Cicero lacteus orbis (milky circle)
• Pliny lacteus circulus (milky circle)

We have been calling white liquids “milk” since Old English. But please don’t drink spurge milk (i.e. its white, latex-like sap), since it’s poisonous:

Wið weartan genim þysse ylcan wyrte [sc. spurge's] meolc & clufþungan wos, do to þære weartan. 
Pseudo-Apuleius' Herbarium

“With warts, take the wort (spurge’s) milk & clove-tongues ooze, apply to the warts”

Another pretty old use of the word refers to milk of fish (now called milt). You can eat this, but it’s fish semen:

When þe femele [fish] leggeþ eyren oþer pisen, þe male cometh aftir and shedith his mylke vpon þe eyren and al..þat ben y-touched wiþ þe mylk of þe male shal be ffysshe.
(a1398) Trev.Barth.

From about the same time we start seeing the types of milks you mention in the question:

Cawdel of Almand mylk. Take Almandes blanched and drawe hem up with wyne, [etc.].
(a1399) Form Cury

For more examples refer to the MED.

English speakers have been calling white liquids “milk” since Old English. But please don’t drink spurge milk (i.e. its white, latex-like sap), since it’s poisonous:

Wið weartan genim þysse ylcan wyrte [sc. spurge's] meolc & clufþungan wos, do to þære weartan. 
Pseudo-Apuleius' Herbarium

“With warts, take the wort (spurge’s) milk & clove-tongues ooze, apply to the warts”

Another pretty old use of the word refers to milk of fish (now called milt). You can eat this, but it’s fish semen:

When þe femele [fish] leggeþ eyren oþer pisen, þe male cometh aftir and shedith his mylke vpon þe eyren and al..þat ben y-touched wiþ þe mylk of þe male shal be ffysshe.
(a1398) Trev.Barth.

From about the same time we start seeing the types of milks you mention in the question:

Cawdel of Almand mylk. Take Almandes blanched and drawe hem up with wyne, [etc.].
(a1399) Form Cury

For more examples refer to the MED.

Another thing worth mentioning is the Milky Way. You should not attempt to drink the Milky Way either. The expressions “milky circle” and “galaxy” are older (Bartholomaeus Anglicus' De Proprietatibus Rerum (translation), 1398) but ultimately those expressions were said in Greek or Latin well before the English:

• Hellenistic Greek γαλαξίας (“galaxy”)
• Ancient Greek γάλα “gála” meaning milk, milky sap, or the Milky Way
• Classical Latin lactea via (milky way)
• Cicero lacteus orbis (milky circle)
• Pliny lacteus circulus (milky circle)