The most common and most likely answer to this crossword clue is the 5 letter word SPAWN
S
P
A
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More clues leading to the result SPAWN
Buddy explains!

The straight part
We know that "Offspring" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case offspring = spawn.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 SPAWN mean?
SPAWN verb- To produce or deposit (eggs) in water.
- To generate, bring into being, especially non-mammalian beings in very large numbers.
- To bring forth in general.
- To induce (aquatic organisms) to spawn.
- To plant with fungal spawn.
- To deposit (numerous) eggs in water.
- To reproduce, especially in large numbers.
- (of a character or object) (To cause) to appear spontaneously in a game at a certain point and time.
- The numerous eggs of an aquatic organism.
- Mushroom mycelium prepared for (aided) propagation.
- (by extension, sometimes derogatory) Any germ or seed, even a figurative source; offspring.
- The buds or branches produced from underground stems.
- The location in a game where characters or objects spontaneously appear.