Present put on a tree, oddly (6)
I believe the answer is:
donate
'present' is the definition.
(donating is a kind of presenting)
'put on a tree oddly' is the wordplay.
'put on' becomes 'don' ('don' can be a synonym of 'put on'**).
'oddly' indicates alternate letters.
The alternating letters of 'tree' are 'te'.
'don'+'a'+'te'='DONATE'
(Other definitions for donate that I've seen before include "Give as gift, say blood" , "Make a gift of" , "Contribute charitably" , "Give (transplant organ)" , "Give money to charity" .)