Of or producing or containing serum WordNet 3.0 & Open English WordNet

Containing, secreting, or resembling serum; watery; a fluid or discharge that is pale yellow and transparent, usually representing something of a benign nature. (This contrasts with the term sanguine, which means blood-tinged and usually harmful.). Wiktionary

Containing, secreting, or resembling serum. Wiktionary (translation)