Of or involving the cells of an organization or movement: The assessment of opposition to any totalitarian regime ... is notoriously difficult, for any effective movement must be secretive and cellular (Anthony Sampson). 4. Of or relating to a cellular telephone.
In the past, a human generation has been considered to be 20-25 years. Older genealogical documents will use these numbers. However, genealogical studies have revealed that this is too simplistic and can result in large inaccuracies during statistical calculation.
Gestation period, the duration of pregnancy, in humans being about 266 days (38 weeks) from the time of fertilization until birth 3.  266 days is the average gestation period for humans from conception to birth 4. End of Week 38. (266 Days from Conception) - Estimated birth date. 5.