Strangely worded play seen regularly (5)
I believe the answer is:
oddly
'strangely' is the definition.
(I know that strangely can be written as oddly)
'worded play seen regularly' is the wordplay.
'seen regularly' indicates alternate letters.
'worded'+'play'='wordedplay'
The alternate letters of 'wordedplay' are 'ODDLY'.
(Other definitions for oddly that I've seen before include "in a curious way" , "Weirdly" , "This clue [32A] is not numbered so" , "In a strange manner" , "not in the usual way" .)