proceeding, made, or occurring without definite aim, reason, or pattern

the random selection of numbers.

Statistics . of or characterizing a process of selection in which each item of a set has an equal probability of being chosen.

Building Trades .

(of building materials) lacking uniformity of dimensions

random shingles.

(of ashlar) laid without continuous courses.

constructed or applied without regularity

random bond.

Chiefly British . bank 3 ( def. 7b ) .

Building Trades . without uniformity

random-sized slates.

at random, without definite aim, purpose, method

or adherence to a prior arrangement; in a haphazard way

Contestants were chosen at random from the studio audience.

adjective

definite , methodical , particular , specific , systematic

adjective

accidental , adventitious , aimless , arbitrary , casual , contingent , designless , desultory , driftless , fluky , fortuitous , hit-or-miss * , incidental , indiscriminate , irregular , objectless , odd , promiscuous , purposeless , slapdash * , spot , stray , unaimed , unconsidered , unplanned , unpremeditated , chance , haphazard , hit-or-miss , aleatory , capricious , discretionary , fickle , gratuitous , hazarded , impulsive , intermittent , occasional , sporadic , stochastic , wanton