Confused head of department covered with dirt was first (7)

'confused' is the definition.
(muddling is a kind of confusing)

'head of department covered with dirt was first' is the wordplay.
'head of' says to take the initial letters.
'covered with' says to put letters next to each other (in a down clue, some letters go on top of others).
'dirt' becomes 'mud' (mud is a kind of dirt).
'was first' becomes 'led' (to lead is to go first).
The first letter of 'department' is 'd'.
'd' put after 'mud' is 'mudd'.
'mudd'+'led'='MUDDLED'