Throw softly (4)
(Other definitions for lob that I've seen before include "High shot" , "sky" , "This clumsy fellow" , "Shot of Murray" , "Propel in a high arc" .)
'throw softly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for toss that I've seen before include "Heads or tails throw" , "cast" , "Ditch" , "Casual throw" , "when ship does this?" .)