Perhaps lifeguard’s singular state (5)
I believe the answer is:
saver
'perhaps lifeguard's' is the definition.
I can't judge whether this definition defines the answer.
'singular state' is the wordplay.
'singular' becomes 's' (abbreviation sometimes used in dictionaries).
'state' becomes 'aver' (both can mean to declare).
's'+'aver'='SAVER'
Can you help me to learn more?
(Other definitions for saver that I've seen before include "Cheap fare" , "Reduced travel fare" , "Investor" , "One budgeting" , "One putting money by" .)