noun
A tool used for gripping, bending, or cutting wire and small objects. Often used in metalworking and crafts.
針金を曲げるのにやっとこを使った。
I used pliers to bend the wire.
職人がやっとこで小さな部品をつまんでいる。
The craftsman is picking up a small part with pincers.
The origin is uncertain. It may be related to the verb やっと (to do something with effort), but the exact derivation is unclear.