気味【ぎみ】

気味 (ぎみ) goes straight after a noun or a verb's ます-stem and means "a touch of", "a bit": the state has started to show but is not full-blown. It almost always describes something unwelcome – health, tiredness, a schedule slipping.

The verb goes in the ます-stem, not the dictionary form: ×疲れる気味, ×下がる気味.

Before a noun, and as an adverb

気味 behaves like a noun. Before another noun it takes の; to describe how something is done it takes に; with だ or です it ends the sentence.

気味 or がち

がち says something happens often, as a habit. 気味 says a state is showing a little, now.

気味 read きみ

The same characters read きみ in きみがわるい気味が悪い mean "creepy". That is a separate word, not this suffix.