mass noun
1- the action of dividing or splitting something into two or more parts分裂：
the party dissolved into fission and acrimony.
该政党因分裂而在一片吵闹声中解散了。
1.1
- short for NUCLEAR FISSON.NUCLEAR FISSION的简称。
1.2
- Biology reproduction by means of a cell or organism dividing into two or more new cells or organisms【生】（细胞或有机体的）分裂; 裂殖：
bacteria divide by transverse binary fission.
细菌以横向二分裂的方式繁殖。
no obj.
- (chiefly of atoms) undergo fission（多指原子）裂变：
these heavy nuclei can also fission.
这些重原子核也可裂变。
词源
early 17th cent.: from Latin fissio（n-）， from findere 'to split'.