Spread the word, say, about public relations (5)
I believe the answer is:
spray
'spread the word' is the definition.
'spray' can be an answer for 'spread' (thesaurus). I am unsure of the 'the word' bit.
'say about public relations' is the wordplay.
'about' means one lot of letters goes inside another.
'public relations' becomes 'pr'.
'say' enclosing 'pr' is 'SPRAY'.
Can you help me to learn more?
(Other definitions for spray that I've seen before include "Atomiser or nebuliser" , "Cloud of flying drops" , "Cloud of flying droplets" , "posy of flowers" , "Spindrift, flower bunch" .)