Wanders with headless German men (4)
I believe the answer is:
errs
'wanders' is the definition.
(I've seen this in another clue)
'with headless german men' is the wordplay.
'with' means one lot of letters go next to another.
'headless' means to remove the first letter.
'german' becomes 'ger' (abbreviation).
'men' becomes 'rs' (I can't justify this - if you can you should believe this answer much more).
'ger' with its initial letter removed is 'er'.
'er' next to 'rs' is 'ERRS'.
Can you help me to learn more?
(Other definitions for errs that I've seen before include "Goes astray" , "Goes wrong" , "Is mistaken" , "Sins" , "Slips up" .)