Verbally compare fungus with algae (6)
I believe the answer is:
lichen
'fungus with algae' is the definition.
I know that both 'fungus' and 'algae' relate to this answer.
'verbally compare' is the wordplay.
'verbally' shows a homophone (sound like).
'compare' becomes 'liken' (synonyms).
'liken' is a homophone of 'LICHEN'.
Can you help me to learn more?
(Other definitions for lichen that I've seen before include "Compound plant of fungus and alga" , "Tiny plants growing on rocks and treetrunks" , "Simple plant often found growing on rocks" , "Plants found on tree trunks etc" , "reindeer nibbles" .)