constituting a beginning; giving origin to something derived or developed; original; elementary

primordial forms of life.

Embryology . first formed.

pertaining to or existing at or from the very beginning

primordial matter.

adjective

last , latest

adjective

basic , early , elemental , first , fundamental , original , prehistoric , primal , primary , prime , primeval , primitive , pristine , radical , earliest , initial , maiden , pioneer , elementary