Without reason, Don tripped in a tram (2,6)
I believe the answer is:
at random
'without reason don tripped in a tram' is the definition.
I can't tell whether this definition defines the answer.
'don tripped in a tram' is the wordplay.
'tripped' is an anagram indicator (I've seen 'trips' mean this).
'in' means one lot of letters goes inside another.
'don' anagrammed gives 'ndo'.
'a'+'tram'='atram'
'ndo' going into 'atram' is 'AT RANDOM'.
Can you help me to learn more?
(Other definitions for at random that I've seen before include "Casually" , "In no prearranged order" , "Haphazardly" , "willy-nilly" , "Indiscriminately" .)