Meaning:
to have one’s mouth open in a state of shock, astoundment or awe

Usage example:
目の前で自分の家が燃えているという事態に、彼はあんけとしていた。 (At the sight of his house burning he stood there in shock with his mouth open.)

Meaning:
1. mouth open wide, gape, agape
2. open mouth in wonder/amazement

Usage Example:
1. 弟は美味しそうなハンバーガーが運ばれてくると、あんぐりと口を開けて食べ始めた。 (After getting a tasty looking hamburger, my brother opened his mouth wide and started eating.)
2. 彼の合計点数を聞き、姉はあんぐりとしたまま何も言えなくなっていた。 (After seeing his total score, his sister just stood there speechless and with an open mouth.)

Variations:
あんごり

Meaning:
cry out in a loud voice, the sound of someone crying out loud

Usage Example:
父親に厳しく叱りつけられ、その男の子はあんあんと声を上げて泣いた。 (The boy was crying out loud as his father scolded him.)

Meaning:
open mouth wide, say aah

Usage Example:
とてもお腹がすいていたので、あんと大口を開けて私はステーキを口に入れた。 (I was very hungry, so I opened my mouth wide and ate some steak.)

Variations:
あーん, ああん, アーン

Meaning:
notice something in surprise and possibly let out an involuntary sound

Usage Example:
誰にも喋ってはいけない、と言われていたことを思いだし、私はあわわと口を閉じた。 (I just remembered I was told to keep quiet and hastily shut my mouth.)

Meaning:
to lose self confidence, to be unable to concentrate

Usage Example:
教科書を忘れたことに気づかないまま授業が始まってしまい、僕はあわあわしながら手を挙げた。 (Class had already started when I realized I forgot my textbook; I raised my hand hesitantly.)

Meaning:
clear, obvious

Usage Example:
羽根の模様があらりとしているものが高値で取引される。

Meaning:
vague, uncertain, ambiguous

Usage Example:
条件があやふやな状態で契約を結んでしまい、私たちはすっかり困っている。 (We don’t know what to do after having signed that contract with provisions we’re unsure of.)

Meaning:
chew food, etc. (baby talk)

Usage Example:
その子は親の怒りなど気にも留めず、あむあむと柔らかいパンを頬張っていた。 (That kid didn’t mind his parents getting mad at him, he just kept stuffing his face with bread.)

Meaning:
backwards, opposite, wrong way, in reverse order, contrary

Usage Example:
失敗の原因はまるであべこべな手順で実験を進めたことだった。 (The reason for the experiment failing was a backwards manual.)