Meaning:
1. to open and close mouth, to struggle for air in water (similar to appu appu – あっぷあっぷ)
2. the voice or sound of a happy baby that is just starting to talk
2. to be afraid, feel chilly, fearful

Usage Example:
1. 海水を大量に飲み込み、その人はあぶあぶともがいた。 (That person struggled from drinking huge amounts of sea water.)
2. 嬉しそうな顔をした赤ん坊が、あぶあぶと言葉にならない声を漏らした。 (The happy looking baby made a sound words can’t describe.)