Old theologian left yard in a strange way (5)
I believe the answer is:
oddly
'in a strange way' is the definition.
(I've seen this before)
'old theologian left yard' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'theologian' becomes 'dd' (Doctor of Divinity degree).
'left' becomes 'l' (common abbreviation).
'yard' becomes 'y'.
'o'+'dd'+'l'+'y'='ODDLY'
(Other definitions for oddly that I've seen before include "Strangely, curiously" , "strange to say?" , "In a strange manner" , "Unusually" , "Weirdly" .)