The most common and most likely answer to this crossword clue is the 9 letter word THINGUMMY
I've seen this crossword clue in The Guardian
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More clues leading to the result THINGUMMY
- Slim, toothless person whose name one's forgotten.
- Whatsit’s scrawny and toothless
- Can containing hot and sticky what-d’you-call-it
- Door fastener almost entering stomach, handle I can’t retrieve?
- Lean on sticky, unknown object
- Gadget comprising short flexible joint inside bay window
- Stick-like and sticky? But the name hasn’t stuck!
- Emaciated toothless person whose name I can’t recall
- Poor toothless fellow, whose name I can’t remember
- So-and-so’s pasty, initially short on filling?
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does THINGUMMY mean?
THINGUMMY noun- A thing (used in a vague way to refer to something whose name one cannot recall).
- Penis.
- A person whose name is either unknown or forgotten