hypotheses

n. explanation which gives a reason for observed phenomena, theory (especially in the sciences); supposition, assumption

A hypothesis (from Greek ) consists either of a suggested explanation for a phenomenon or of a reasoned proposal suggesting a possible correlation between multiple phenomena. The term derives from the  Greek, hypotithenai meaning "to put under" or "to suppose." The scientific method requires that one can test a scientific hypothesis. Scientists generally base such hypotheses on previous observations or on extensions of scientific theories.
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Noun
1. a proposal intended to explain certain facts or observations
(hypernym) proposal
(derivation) speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose
2. a tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; "a scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices"
(synonym) possibility, theory
(hypernym) concept, conception, construct
(hyponym) model, theoretical account, framework
(part-holonym) theory
(derivation) speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose
3. a message expressing an opinion based on incomplete evidence
(synonym) guess, conjecture, supposition, surmise, surmisal, speculation
(hypernym) opinion, view
(hyponym) divination
(derivation) speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose

n. hypothesis, assumption, guess work, surmise, supposition

(pl. )
of Hypothesis