The most common and most likely answer to this crossword clue is the 3 letter word SIP
S
I
P
More clues leading to the result SIP
Buddy explains!

The straight part
We know that "take a wee dram" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case take a wee dram = sip.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 SIP mean?
SIP verb- To ooze or pass slowly through pores or other small openings, and in overly small quantities; said of liquids, etc.
- To enter or penetrate slowly; to spread or diffuse.
- To diminish or wane away slowly.
- A small mouthful of drink
- To drink slowly, small mouthfuls at a time.
- To drink a small quantity.
- To taste the liquor of; to drink out of.
- To consume slowly — in contrast to faster consumption, in contrast to zero consumption