Behold around the East a sign (3)
I believe the answer is:
leo
'a sign' is the definition.
(star sign)
'behold around the east' is the wordplay.
'behold' becomes 'lo' (archaic exclamation meaning 'look!').
'around' is an insertion indicator.
'the east' becomes 'E' (abbreviation).
'lo' enclosing 'e' is 'LEO'.
(Other definitions for leo that I've seen before include "Singer-songwriter Sayer, b. 1949" , "Name taken by 13 popes, the last dying in 1903 aged 93" , "sign of summer" , "Lion sign of the Zodiac" , "Astrological sign" .)