What is the meaning of Solum?

Within a soil profile, a set of related soil horizons that share the same cycle of pedogenic processes; the upper layers of a soil profile that are affected by climate.

bottom, ground, base, foundation, bed

floor, pavement

ground, earth, land, soil

sole (of the foot)

land, country, region, place

only, just, barely, merely

inflection of sōlus: nominative/accusative/vocative neuter singular accusative masculine singular

nominative/accusative/vocative neuter singular

accusative masculine singular

dative plural of sol (“mud”)

Source: Wiktionary