What is the etymology of the term 'hunch'?

Question

Oxford states the etymology as:

late 15th century: of unknown origin. The original meaning was ‘push, shove’ (noun and verb), a sense retained now in Scots as a noun, and in US dialect as a verb. [The] noun derives probably from a US sense of the verb ‘nudge someone in order to draw attention to something’.

Hunch in Scots means 'push' as a noun. Did the Scots not use it as a verb? Why did the US use it as a verb?

In the example below, the meaning of 'hunched over' is 'bent over' according to the Guided Compositions book.

The usual hectic traffic awaited me as I hunched over the steering wheel of the company car.

Answer 1

OED states that the verb hunch is of obscure origin but tries to explain the sense-development:

Of obscure origin: but compare hinch v. If sense II.3 belongs to the same word as senses I.1 and I.2 (which is doubtful), the sense-development may have been ‘to thrust or shoot out’, ‘to cause to stick out’, and hence ‘to form a projection or protuberance’.

and notes that the typical meaning of the verb 'hunch' is first observed in the compound word 'hunch-backed':

It is noteworthy that the first trace of sense II.3 appears, not in the simple hunch verb or noun, but in the combination hunch-backed substituted in the 2nd Quarto of Shakespeare's Richard III (1598) iv. iv. 81, for the earlier and ordinary 16–17th cent. word bunch-backed...

_{Oxford English Dictionary, s.v. “hunch (v.), Etymology,” March 2024, https://doi.org/10.1093/OED/7981692207.}

_{Note: I haven’t cited the entire note about hunch-backed in OED because it is lengthy and not particularly relevant.}

For the noun hunch, OED states that the original sense is formed by conversion, and includes a brief etymology for its other senses:

In sense 1 < hunch v.; in sense 2 apparently deduced < hunch-backed. Sense 3 may belong to a distinct word; this, although known only from 1790, is found in popular use before 1830 in southern and northern dialects, in the West Indies, and in New England. Compare also hunk n.¹ in same sense, exemplified from 1813.

OED also lists the adjective hunch and adds that it is perhaps formed within English, by conversion from the verb hunch. It is listed as a dialectal word meaning "That shrivels or pinches (with cold)." _{- Oxford English Dictionary, s.v. “hunch (adj.),” July 2023, https://doi.org/10.1093/OED/5057064459.}