jittery

the word 'jittery' is a relatively modern american english formation from the early 20th century. its core, 'jitter,' is likely an onomatopoeic or imitative creation, mimicking the concept of rapid, shaky, or nervous movement. the suffix '-y,' with its ancient germanic lineage from proto-germanic -igaz and ultimately proto-indo-european -kos, is a highly productive adjective-forming element meaning 'characterized by' or 'resembling.' thus, the literal construction 'full of the jitters' logically evolved to describe both a psychological state of nervous anxiety and the physical manifestation of unsteady, trembling motion.

Structure: jitter (to shake nervously) + y (adjective-forming suffix) jitter (origin uncertain, likely imitative of shaky movement; functions as the base noun/verb). y (old english -ig, germanic adjective-forming suffix; indicates 'characterized by' or 'full of').