ROGET THESAURUS
diffusion
Dispersion
N
nonassemblage, dispersion, dispersion, disjunction, divergence, aspersion, scattering, dissemination,
diffusion, dissipation, distribution, apportionment, spread, respersion, circumfusion, interspersion, spargefaction, affusion, waifs and estrays, flotsam and jetsam, disjecta membra waveson, unassembled &c (assemble), dispersed, sparse, dispread, broadcast, sporadic, widespread, epidemic, adrift, stray, disheveled, streaming, sparsim, here and there, passim.
Presence
N
presence, occupancy, occupation, attendance, whereness, permeation, pervasion,
diffusion, ubiety, ubiquity, ubiquitariness, omnipresence, bystander, present, occupying, inhabiting, moored, resiant, resident, residentiary, domiciled, ubiquitous, ubiquitary, omnipresent, universally present, peopled, populous, full of people, inhabited, here, there, where, everywhere, aboard, on board, at home, afield, here there and everywhere, in presence of, before, under the eyes of, under the nose of, in the face of, in propria persona, on the spot, in person, in the flesh, nusquam est qui ubique est.
Rarity
N
rarity, tenuity, absence of solidity, subtility, subtilty, subtlety, sponginess, compressibility, rarefaction, expansion, dilatation, inflation, subtilization, vaporization, evaporation,
diffusion, gassification, ether, rare, subtile, thin, fine, tenuous, compressible, flimsy, slight, light, cavernous, spongy, rarefied, unsubstantial, uncompact, incompressed, rarefiable.