This is the 12785th most frequent Portuguese word.
velhas
"Velhas" means "old women" or "old" (feminine plural).
Here, 'velhas' describes 'roupas' (clothes) and conveys the meaning of 'old' or 'used and aged.'
As roupas velhas foram doadas para caridade.
The old clothes were donated to charity.
In this sentence, 'velhas' modifies 'amigas' (friends) and can imply 'long-standing' or 'friends from a long time ago.'
Minhas velhas amigas sempre me visitam.
My old friends always visit me.
The word 'velhas' here qualifies 'livros' (books), signifying their age, though 'livros' should be masculine, causing agreement issues in standard Portuguese ('velhos' would be correct).