'Thallus' definitions:
Definition of 'thallus'
(from WordNet)
noun
A plant body without true stems or roots or leaves or vascular system; characteristic of the thallophytes
Definition of 'Thallus'
From: GCIDE
- Thallus \Thal"lus\, n.; pl. Thalli. [NL., fr. Gr. ? young shoot or branch, frond.] (Bot.) A solid mass of cellular tissue, consisting of one or more layers, usually in the form of a flat stratum or expansion, but sometimes erect or pendulous, and elongated and branching, and forming the substance of the thallogens. [1913 Webster]