s, e, f, n, c, m, r, t, y are letters that make 'reference system'
ER, system, re, te, ref, em, en, refer, CE, stem, reference, NC, Re, Ce, Er, Fe, Te are words within 'reference system'
1 possible definitions for 'reference system'
Under this definition, reference system is a noun and has the following properties:
coordinate system, frame of reference, reference frame have the same meaning as 'reference system'
'reference system' can be a type of arrangement, organization, organisation, system.
Cartesian coordinate system, inertial reference frame, inertial frame, space-time, space-time continuum are types of 'reference system'.
coordinate axis is a part of reference system.