scram

Probably either:

a clipping of scramble by apocope; or

from dialectal German schramm, the imperative singular form of schrammen (“to scratch, scrape”), from Late Middle High German schramm, schramme (“a graze, scratch”); further etymology unknown.

Uncertain; the verb is possibly derived from etymology 1. It has been suggested that the word is an acronym for phrases like “safety control rod actuator mechanism”, “safety cut rope axe man”, “safety control rod axe man”, and “safety control rods activation mechanism”, but these are most likely backronyms.

The noun is probably derived from the verb.

Origin unknown.