semen (n.)

Middle English souen, from Old English sawan "to scatter seed upon the ground or plant it in the earth, disseminate" (class VII strong verb; past tense seow, past participle sawen), from Proto-Germanic *sean (source also of Old Norse sa, Old Saxon saian, Middle Dutch sayen, Dutch zaaien, Old High German sawen, German säen, Gothic saian).

This is reconstructed to be from PIE root *sē- "to sow," source of semen, season (n.), seed (n.). The figurative sense of "spread abroad, disseminate" was in Old English; of physical things other than seed, "scatter over, besprinkle," mid-14c. Related: Sowed, sown; sowing. Sowing machine "device for sowing seed" is by 1812.

Proto-Indo-European root meaning "to sow." 

It forms all or part of: disseminate; inseminate; seed; seme (adj.); semen; seminal; seminar; seminary; semination; sinsemilla; sow (v.); season.

It is the hypothetical source of/evidence for its existence is provided by: Latin serere "to sow;" Old Church Slavonic sejo, sejati; Lithuanian sju, sti "to sow;" Old English sawan "to sow;" Old Prussian semen "seed," Lithuanian smenys "seed of flax," Old Church Slavonic seme, Old High German samo, German Same; Old English sed, sd "that which may be sown; an individual grain of seed."