The most common and most likely answer to this crossword clue is the 6 plus 6 letter word LONELY HEARTS
I've seen this crossword clue in The Daily Telegraph
L
O
N
E
L
Y
H
E
A
R
T
S
More clues leading to the result LONELY HEARTS
- With little love, they learn to adapt in empty lives?
- Yell on poor football team: they’re looking for a match?
- They need dates in 51 Harley St to get treatment
- They hope to get dates at 51 Harley St to be treated
- Single people new in hostelry getting drunk with ale
- Really honest bubbly people seeking mates
- Singletons?
Buddy explains!
The straight part
We know that "people seeking mates" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case people seeking mates = lonely hearts.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.