Passionate old travellers in retirement going to America (7)
I believe the answer is:
amorous
'passionate' is the definition.
(similar in meaning)
'old travellers in retirement going to america' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'travellers' becomes 'roma' (Romani people).
'in retirement' shows that the letters should be reversed in order (retire can mean to go back or backwards).
'going to' says to put letters next to each other.
'america' becomes 'us' (United States).
'o'+'roma'='oroma'
'oroma' reversed gives 'amoro'.
'amoro'+'us'='AMOROUS'
(Other definitions for amorous that I've seen before include "Feeling or showing romantic love" , "Showing desire" , "Lovong" , "Possessed of loving or romantic feeling" , "Fond" .)