What does the cryptic crossword clue "Reptile found when bottom of jar removed (4)" mean?

The definition is "Reptile". The wordplay uses a deletion. CROC (deletion) = CROC; definition: "Reptile" The answer is CROC.

Reptile found when bottom of jar removed (4)

Guardian Cryptic #29653 | 22 Down | 2025-03-27 flower