1. Being or operating under the surface of the earth
   - subterranean 
2. Lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed)
   - subterranean, ulterior

See also: covert, subsurface

• croaker
• croaking
• croaky
• Croat
• Croatia
• Croatian
• croc
• Crocanthemum canadense
• Crocethia
• Crocethia alba
• crochet
• crochet hook
• crochet needle
• crochet stitch
• crocheting
• crocidolite
• crock
• Crock Pot
• crock up
• crocked
• crockery
• crocket
• crocketed
• Crockett
• crocodile