With unusual old tree, I stood around (8)
I believe the answer is:
loitered
'around' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can occasionally define each other.
'with unusual old tree i stood' is the wordplay.
'with' indicates putting letters inside.
'unusual' indicates anagramming the letters.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'stood' becomes 'ld' (I can't explain this - if you can you should give a lot more credence to this answer).
'o'+'tree'+'i'='otreei'
'otreei' is an anagram of 'oitere'.
'oitere' inserted within 'ld' is 'LOITERED'.
Can you help me to learn more?
(Other definitions for loitered that I've seen before include "Hung around idly, dawdled" , "Dallied" , "Stood around aimlessly" , "Kicked heels" , "dilly-dallied" .)