This is the 11142nd most frequent Catalan word.
sus
"Sus" in Catalan means "scare" or "fright."
In this sentence, 'Sus' means 'Her' and indicates possession referring to 'eyes'.
Sus ulls brillen amb intensitat quan somriu.
Her eyes shine brightly when she smiles.
Here, 'Sus' is used as an adverb meaning 'upstairs' or 'above'.
Estaven sus, observant cada moviment.
They were upstairs, observing every movement.
In this context, 'Sus' again functions as an adverb meaning 'above'.