unstable English · revision 15313

+ {{infobox|confidence=established|formation=derivation|attested=c. 1200}}

+

+ ==Pronunciation==

+ * IPA: /ʌnˈsteɪ.bəl/^(Wiktionary)

+

+ ==Etymology==

+ It is [[af|en|un-|stable]].^(Etymonline)^(MWU 2024) A similar formation is [[gmh|unstabel]].^(Etymonline)

+

+ ==Earliest recorded meaning==

+ Apt to move, not staying steadily in place: about 1200 in Etymonline, before 1225 in the OED.^(Etymonline)^(OED 1989)

+

+ ==Semantic evolution==

+ Fickle, vacillating or changeable is from the late 13th century (about 1290),^(Etymonline)^(OED 1989) liable to fall from about 1300,^(Etymonline) and structurally insecure by the late 14th century.^(Etymonline) Not fixed in condition, exposed to chance, is from about 1340.^(OED 1989) Technical senses follow: unstable equilibrium in mechanics (1839), unstable compounds in chemistry (1849) and in physics (1904).^(OED 1989) An Old English word for the idea was [[m|ang|feallendlic]].^(Etymonline)

+

+ ==Timeline==

+ * c. 1200 – apt to move.^(Etymonline)

+ * c. 1290 – fickle.^(OED 1989)

+ * c. 1300 – liable to fall.^(Etymonline)

+ * 1849 – unstable compounds.^(OED 1989)

+

+ ==Modern meaning==

+ ===Adjective===

+ # Likely to change or fail; not [[stable]] or firm.^(AHD)^(Collins 2023)

+ # Not firmly fixed; likely to fall or give way.^(AHD)

+ # Of a person, given to unpredictable changes of mood or behaviour.^(AHD)^(Collins 2023)

+ # ''(chemistry, physics)'' Readily decomposing or decaying, as a [[radioactive]] substance.^(AHD)^(Collins 2023)

+

+ ==Word family==

+ * [[unstableness]]

+ * [[unstably]]

+

+ ==Related words==

+ * [[instability]]

+ * [[stable]]

+ * [[stand]]

+

+ ==References==

+ {{reflist}}