The most common and most likely answer to this crossword clue is the 5 letter word GRANT
I've seen this crossword clue in The Times
G
R
A
N
T
More clues leading to the result GRANT
- Allow elderly relative time
- President with the heart for angry demagogy
- 19th century president's allowance
- General entitlement
- Acknowledge galleon’s first broadside
- Present relative temperature
- Allow wild speech supporting head of government
- Republican president’s ultimately jaw-dropping tirade
- Permit head of geography to deliver a tirade
- Financial support for Hugh maybe
Buddy explains!

The straight part
We know that "19th century president/allowance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case 19th century president/allowance = grant.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 GRANT mean?
GRANT noun- The act of granting; a bestowing or conferring; concession; allowance; permission.
- The yielding or admission of something in dispute.
- The thing or property granted; a gift; a boon.
- A transfer of property by deed or writing; especially, an appropriation or conveyance made by the government.
- The deed or writing by which such a transfer is made.
- An application for a grant (monetary boon to aid research or the like).
- (ditransitive) to give (permission or wish)
- (ditransitive) To bestow or confer, with or without compensation, particularly in answer to prayer or request; to give.
- To agree with (someone) on (something); to accept (something) for the sake of argument; to admit to (someone) that (something) is true.
- To assent; to consent.