Pitiful debilitating affliction like case of lurgy (6)
I believe the answer is:
'pitiful' is the definition.
(both can mean be used to mean small or pathetic)
'debilitating affliction like case of lurgy' is the wordplay.
'debilitating affliction' becomes 'ME' (short for myalgic encephalomyelitis).
'like' becomes 'as'.
'case of' means to remove the middle letters (outsides of).
'lurgy' with its middle taken out is 'ly'.
(Other definitions for measly that I've seen before include "contemptibly inadequate", "description of child's complaint", "Insignificant a having spots!", "Contemptibly small in amount", "Spotted in bed, perhaps".)