The most common and most likely answer to this crossword clue is the 5 plus 6 letter word THIRD PERSON
I've seen this crossword clue in The Times
T
H
I
R
D
P
E
R
S
O
N
More clues leading to the result THIRD PERSON
- She perhaps is in shorter novel about the origins of diverse peoples
- Another like Eva and Juan possessing son like theirs
- Maybe they have shaken north's pride
- He or she maybe the winner of the bronze
- She possibly reports hand straying after American leaves for Italy
- Husband intercepted pints order sent out for someone else
- He is following two others
- Neither compiler nor solver could be murderer
- He must be Cain
- . Say, he inspired others to frequently issue releases differently
Buddy explains!

The straight part
We know that "like theirs" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case like theirs = third person.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.