ὑπότρομος
From LSJ
λίγεια μινύρεται θαμίζουσα μάλιστ' ἀηδών → the sweet-voiced nightingale mourns constantly, the sweet-voiced nightingale most loves to warble
English (LSJ)
ον,
A quivering, shaking, Plu.2.435b; somewhat afraid or timid, Aeschin.3.159, Luc. DDeor.19.1, etc.