ぺこんsound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head

ぶつけた鍋(なべ)がぺこんと凹(へこ)みました。

The pot that was struck caved in with a sound like thin metal or plastic surface caving in and springing back. {sound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head}

缶(かん)蹴(け)りに使(つか)われていた缶(かん)がペコんとへこんでいる。

The can that was being used for kick-the-can is dented, with a bob of the head-like caving in and springing back. {sound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head}

小学生(しょうがくせい)が先生(せんせい)に向(む)かってぺこんとおじぎをしています。

The elementary school student is giving a quick bow, with a bob of the head, towards the teacher. {sound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head}

押(お)すとぺこんとへこむこのフライパンは見(み)るからに不(ふ)良品(りょうひん)だ。

This frying pan, which dents and springs back when pushed, clearly looks like a defective product just by looking at it. {sound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head}

僕(ぼく)にぶつかってきた人(ひと)を睨(にら)みつけるとその人(ひと)はぺこんとおじぎをした。

When I glared at the person who bumped into me, they quickly bowed their head with a bob. {sound of thin metal or plastic surface caving in and springing back, action of quickly bowing or lowering one's head, (with a) bob of the head}