Nouns

(n)operating expense, operating cost, overhead, budget itemsthe expense of maintaining property (e.g., paying property taxes and utilities and insurance); it does not include depreciation or the cost of financing or income taxes
(n)command processing overhead time, command processing overhead, command overhead, overhead(computer science) the processing time required by a device prior to the execution of a command
(n)disk overhead, overhead(computer science) the disk space required for information that is not data but is used for location and timing
(n)viewgraph, overheada transparency for use with an overhead projector
(n)overhead(nautical) the top surface of an enclosed space on a ship
(n)overhead, smasha hard return hitting the tennis ball above your head

Adjectives

(a)overheadlocated or originating from above“an overhead crossing”

Adverbs

(r)overheadabove your head; in the sky“planes were flying overhead”
(r)overheadabove the head; over the head“bring the legs together overhead”