grixabybi'otei lujvo

x1 = t1 is the elapsed time required for decaying/diminishing/reducing/shrinking population x2 = g1 to decrease in number by a factor of exactly/approximately half according to standard/under condition/by model/in experiment x3; x1 is the half-life of population/sample x2; the (approximate) halving of population x2 takes approximately x1 (dimensionful number: time).

Many of the veljvo terbri can be derived from those which are present. This word may refer to a duration that is statistical (for large samples, the average time required for half of the population to probably disappear/become invalid), ideal (guaranteed rather than statistical), or experimental (in a given trial, some number was recorded on a stopwatch when the count decreased by half). See also: gritezdybi'otei, grixonbybi'otei.

In notes:

gritezdybi'otei
x1 = t1 is the elapsed time required for decaying/diminishing/reducing/shrinking population x2 = g1 to decrease in number by a factor of exactly/approximately 1/e^(x3) from that which is considered to be the initial population size, where e is the natural exponential base and x3 [li; default: 1] is a real number, according to standard/under condition/by model/in experiment x4; x1 is the one-(e^(x3))-th-life of population/sample x2; the (approximate) (x3)-th one-e-th-ing/e-fold decrease(/increase) of population x2 takes approximately x1 (time).
grixonbybi'otei
x1 = t1 is the elapsed time required for decaying/diminishing/reducing/shrinking population x2 = g1 to decrease in number by a factor of exactly/approximately 1/(x3) from that which is considered to be the initial population size, where x3 [li; default: 1] is a positive real number, according to standard/under condition/by model/in experiment x4; x1 is the (x3^(-1))-th-life of population/sample x2; the (approximate) one-x3-th-ing/(x3)-fold decrease(/increase) of population x2 takes approximately x1 (time).