没意思(méi yì si) - boring, not interesting in Mandarin

没意思 (méi yì si) means boring, and it says so quite literally: 没 (méi), "without", plus 意思 (yìsi), "meaning, interest" - "without interest". The third syllable, 思 (si), loses its tone here and is simply pronounced flat, the way it is in 意思 (yìsi) on its own.

Anything that fails to hold your attention takes 没意思 (méi yì si): a dull film, a book that drags, an afternoon with nothing to do. 一个人在家很没意思 (yí ge rén zài jiā hěn méi yì si), "being at home alone is very boring", is the sort of line a bored teenager reaches for constantly.

Its opposite is 有意思 (yǒu yì si), "interesting" - swap 没 (méi) for 有 (yǒu) and the meaning flips entirely, so listen carefully for which one you are hearing. They rhyme all the way through except that first syllable.