1. A contorted knot in wood; a cross-grained protuberance; a nodule; a boss or projection
   - knurl 
2. A knot in wood; a protuberance
   - knag

Derived forms: knurs

• cytokinesis
• cytokinetic
• cytokinin
• cytol
• cytologic
• cytologic smear
• cytologic specimen
• cytological
• cytologist
• cytology
• cytolysin
• cytolysis
• cytolytic
• cytomegalic
• cytomegalovirus
• cytomembrane
• cytopathogenic
• cytopenia
• cytophotometer
• cytophotometric
• cytophotometrically
• cytophotometry
• cytoplasm
• cytoplasmatic
• cytoplasmic