To pinch or grasp something between the fingers (or pick up with chopsticks/tweezers).
小さなネジを指でつまんで外した。
I pinched the small screw with my fingers and removed it.
箸で刺身をつまんで食べる。
Pick up sashimi with chopsticks and eat it.
パンを一切れつまんで口に入れた。
I pinched off a slice of bread and put it in my mouth.
To pick up and eat (snack on something); to nibble or grab a bite.
テレビを見ながらポテトチップスをつまんでしまった。
I ended up snacking on potato chips while watching TV.
パーティーでは皆が軽くつまめる料理を用意した。
At the party we prepared finger foods everyone could nibble on.
飲みながらつまめるおつまみを買ってきてください。
Please buy snacks that we can nibble on while drinking.
To pick out the main points or summarize — to distill something to its essentials.
長い報告書から要点をつまんでプレゼン用にまとめた。
I picked out the key points from the long report and summarized them for the presentation.
会議では各自が話の重要な部分をつまんで説明した。
At the meeting each person explained the important parts succinctly.
記事の内容をつまんでメモに書いた。
I distilled the article's content and wrote it down as notes.
Rarely, to fascinate or bewitch someone; often appears in passive constructions.
彼女の歌声に観客はつままれた。
The audience was captivated by her singing voice.