UNDERMANNED

undermanned, short-staffed, short-handed, understaffed

(adjective) inadequate in number of workers or assistants etc.; “they’re rather short-handed at the moment”; “overcrowded and understaffed hospitals”

Source: WordNet® 3.1

Verb

undermanned

simple past tense and past participle of underman

Adjective

undermanned (comparative more undermanned, superlative most undermanned)

Insufficiently manned; understaffed

Source: Wiktionary

Un`der*manned", a. (Naut.)

Definition: Insufficiently furnished with men; short-handed.

Source: Webster’s Unabridged Dictionary 1913 Edition