1) Fern genus 2) Genus ceterach 
• (n.) A species of fern with fronds (Asplenium Ceterach).
Cet'e·rach noun [ French cétérac , from Arabic shetrak .] (Botany) A species of fern with fronds ( Asplenium Ceterach ). 
Ceterach is a genus of ferns of the sub-family Polypodiaceae, chiefly known by the reticulated veins, the simple sort, with scarcely any indusium, and the abundance of chaffy scales which clothe the under surface of the leaf. One species, Ceterach officinarum (the scale-fern or miltwaste), is indigenous to Britain, and common on rocks and walls.
[n] - small genus of Old World ferns
genus Ceterach noun small genus of Old World ferns; superseded in some classification systems which place plants of this genus in e.g. genera Asplenium and Pleurosorus