From The Collaborative International Dictionary of English v.0.48:
Clan \Clan\ (kl[a^]n), n. [Gael. clann offspring, descendants;
akin to Ir. clann, cland, offspring, tribe, family; perh.
from L. plania scion, slip, cutting. Cf. Plant, n.]
1. A tribe or collection of families, united under a
chieftain, regarded as having the same common ancestor,
and bearing the same surname; as, the clan of Macdonald.
"I have marshaled my clan." --Campbell.
[1913 Webster]
2. A clique; a sect, society, or body of persons; esp., a
body of persons united by some common interest or pursuit;
-- sometimes used contemptuously.
[1913 Webster]
Partidge and the rest of his clan may hoot me.
--Smolett.
[1913 Webster]
The whole clan of the enlightened among us. --Burke.
[1913 Webster]