This is the 932nd most frequent Japanese word.
食っ
The word "食っ" (kku) is an informal or colloquial form of "食べる" (taberu), meaning "to eat" in English.
『食った』 is used as a colloquial and casual way to say 'ate' in the past tense.
昨夜の晩御飯でカレーをたくさん食った。
I ate a lot of curry for dinner last night.
『食える』 is the potential form of 『喰う (くう)』 meaning 'can eat'.
こんな辛いもの、よく食えるね。
How can you eat something this spicy?
『食って』 is the gerund form of 『喰う (くう)』 used to describe ongoing or habitual actions.