完全かんぜん燃焼ねんしょう
fukanzen nenshō

Noun
Suru Verb

1. incomplete combustion; imperfect combustion

いち酸化さんか炭素たんそとは炭素たんそ化合かごうぶつ完全かんぜん燃焼ねんしょう発生はっせいする有害ゆうがい物質ぶっしつです。
issankatansotowa tansokagōbutsuno fukanzen nenshōde hassē suru yūgai busshitsudesu.
Carbon monoxide is a poisonous substance formed by the incomplete combustion of carbon compounds.
Noun
Suru Verb
Idiomatic Expression

2. being off one's game; not doing one's best; being unable to use all of one's strength; failing to obtain the desired result