na-adjective
Describes a person's actions, speech, or work as lacking skill or finesse; somewhat formal and less common than 不器用 or 下手.
彼の不精巧な説明では誰も納得しなかった。
No one was convinced by his clumsy explanation.
不精巧な細工で、すぐに壊れてしまった。
It broke quickly because of the bungling workmanship.
General word for lack of skill; 不精巧 carries a stronger nuance of being poorly constructed or ineptly executed.
Compound of 不 (negative prefix) and 精巧 (elaborate, exquisite). The exact historical derivation is uncertain, but the meaning follows directly from the components.