The most common and most likely answer to this crossword clue is the 5 letter word INDUE
I
N
D
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E
More clues leading to the result INDUE
Buddy explains!

The straight part
We know that "invest" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case invest = indue.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 INDUE mean?
INDUE verb- To pass food into the stomach; to digest; also figuratively, to take on, absorb.
- To take on, to take the form of.
- To put on (a piece of clothing); to clothe (someone with something).
- To invest (someone) with a given quality, property etc.; to endow.