noun, na-adjective
flaw; defect; malfunction; bug
Broadly used for physical defects, system errors, software bugs, and operational failures. Often appears in technical and business contexts.
このソフトにはまだ不具合がいくつかある。
This software still has several bugs.
機
Production was halted because a malfunction occurred in the machine.
na-adjective
Describes a situation or condition that is inconvenient or not working as desired. Less common than the noun sense.
今の住まいは駅から遠くて不具合だ。
My current place is inconvenient because it's far from the station.
欠陥 is a flaw or defect, often inherent. 不具合 can refer to temporary malfunctions or operational problems.
Compound of 不 (fu, 'not') and 具合 (guai, 'condition, state'). Literally 'not in good condition'.