1. (noun) (embryology) the repeated division of a fertilised ovum

• segmentation

1. (noun) the state of being split or cleft

• state

2. (noun) the breaking of a chemical bond in a molecule resulting in smaller molecules

• chemical action
• chemical change
• chemical process

3. (noun) (embryology) the repeated division of a fertilised ovum

• cell division
• cellular division

4. (noun) the line formed by a groove between two parts (especially the separation between a woman's breasts)

• area
• region

5. (noun) the act of cleaving or splitting

• division

1. (noun) (embryology) the repeated division of a fertilised ovum

• embryology

1. (noun) the act of cleaving or splitting

• cleave
• rive
• split