The most common and most likely answer to this crossword clue is the 6 letter word DROWSY
I've seen this crossword clue in Financial Times
D
R
O
W
S
Y
More clues leading to the result DROWSY
- Wordy novel about society may make one sleepy
- Tired of wordy novel about head of state
- Sleepy and thirsty, suppressing pained cries
- Sleepy daughter fights — last thing mummy needs
- Sleepy, Doc and Sneezy emptied bottles o’ whiskey
- Tired arguments in outskirts of Derby
- Democrat, hopeful, hugging wife, nodding
- Half asleep, young blade gets up
- Arguments between start and end of day dropping off
- Tired words ruined day at last
Buddy explains!

The straight part
We know that "nodding" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nodding = drowsy.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 DROWSY mean?
DROWSY adjective- Inclined to drowse; heavy with sleepiness
- Causing someone to fall sleep or feel sleepy; lulling; soporific.
- Boring.
- Dull; stupid.