i-adjective
bitterish; somewhat bitter
Describes a mild or slightly bitter taste, often used for food or drink. The suffix っぽい adds a nuance of 'having a touch of bitterness'.
このコーヒーは苦っぽくて、あまり好きじゃない。
This coffee is somewhat bitter, so I don't really like it.
苦っぽいチョコレートが大人の味だ。
Bitterish chocolate is an adult taste.