Emergency room supporting soldier with organ donor (6)
I believe the answer is:
gifter
'donor' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'emergency room supporting soldier with organ' is the wordplay.
'emergency room' becomes 'ER' (abbreviation popularized by US TV series).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'soldier' becomes 'gi' (term for US soldier).
'with' is a charade indicator (letters next to each other).
'organ' becomes 'FT' (Financial Times - organ can mean a newspaper).
'gi'+'ft'='gift'
'er' put after 'gift' is 'GIFTER'.
Can you help me to learn more?