Definition of inoculum in US English:


nounPlural inocula

  • A substance used for inoculation.

    • ‘About 20 percent of cases of this disorder occur in otherwise healthy persons who have received a heavy inoculum.’
    • ‘This suspension was the standard inoculum for testing by the method of proportion.’
    • ‘The inoculum used in the present study could absorb the MOLT - 4 cells in a 0.001% of serum concentration.’
    • ‘The inoculum was injected slowly into the bladder to avoid leakage and the catheter was withdrawn carefully.’
    • ‘The inoculum used for medical device applications is typically Bacillus spores.’


Early 20th century: modern Latin, from Latin inoculare (see inoculate), on the pattern of the pair coagulate, coagulum.