The most common and most likely answer to this crossword clue is the 8 letter word BABY-SIT
I've seen this crossword clue in The Times
B
A
B
Y
-
S
I
T
Buddy explains!
The straight part
We know that "mind infant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mind infant = baby-sit.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 BABY-SIT mean?
BABY-SIT verb- To watch or tend someone else's child for a period of time, often for money.
- To watch or attend anything or anyone unnecessarily closely; to have to help or coax too much.