How did 'undertake' evolve to mean 'take on'?

Question

What's an intuitive derivation behind ODO's definition that helps to remember its meaning:

undertake = [with object] 1. Commit oneself to and begin (an enterprise or responsibility); take on:

Etymonline: c.1200, "to entrap;" c.1300, "to set about (to do)," from under + take (v.). Similar formation in French entreprendre "to undertake," from entre "between, among" + prendre "to take." The under in this word may be the same one that also may form the first element of understand. Old English had underniman "to trap, accept" (cognate with Dutch ondernemen, German unternehmen).

How does the prefix under- mean 'on'? Etymonline mentions the French entreprendre, but how does this help? First, entre- is a different preposition. Second, I also don't understand how 'between/among + take' evolves into 'take on' ? I tried Etymonline's page on under- to no avail, esp. because it refers to other languages. Is there a simpler, more intuitive explanation?

Answer 1

One of my favorite resources for this kind of question is the University of Michigan's Middle English Dictionary. There is an entry there for the prefix "under", one of the definitions of which is:

(7) ‘into subjection or subordination, under control, jurisdiction, etc.’ (e.g., the verbs underdon (a), underibringen, underleien 2., underlien 2., underlouten v.(1) (a) & (b), undertheden, underthrouen, underyoken; the noun underthednesse; the participles underbroght (a), underfolde; the gerunds undercasting(e, underputtinge (b); and the adjective underlout(e);

In Middle English, for instance, "underdon" means "observed, placed within the purview of one's eyes" and "underyoken" means "to subjugate."

This gives a plausible explanation of "undertake," as referring to taking something into your power or jurisdiction. The Middle English "undertaken" can also mean "to entrap," or "to take charge of a place," a more direct reference to control.

The MED itself takes a more equivocal stand, saying that in "undertaken" the meaning of the "under" prefix has been "lost or obscured." However, the "control or jurisdiction" seems closer to the modern meaning of the word than "beneath".

The only other modern word I can think of that uses "under" in this sense is "undergo." If you "undergo" an ordeal or a process, you are subject to its authority.

Answer 2

The original English under had several meanings similar to German unter. So one of them ended up in undertake and does not mean beneath in this case, even in the derived form undertaker.

If you want an association to help you remember what it means, I suppose you could imagine an undertaking as list of promises with the signature of the individual who undertakes these underneath the promises. But it would be a false etymology.