Definition of "appall"

appall

/əˈpɔːl/

verb
third-person singular simple present appalls, present participle appalling, simple past and past participle appalled
1. (transitive) To fill with horror and/or indignation; to dismay.
  Quotations
  The house of peers was somewhat appalled at this alarum.
  1702–1704, Edward [Hyde, 1st] Earl of Clarendon, “(please specify |book=I to XVI)”, in The History of the Rebellion and Civil Wars in England, Begun in the Year 1641. […], Oxford, Oxfordshire: Printed at the Theater, published 1707
2. (transitive, obsolete) To make pale; to blanch.
  Quotations
  Thanſwere that ye made to me my derewhañ I did ſewe for my poore hartes redreſſehathe ſo apalld my countenaunce […]
  c. 1527–1542, Thomas Wyatt, “Thanſwere that ye made to me my dere”, in Egerton MS 2711‎, page 63r
3. (transitive, obsolete) To weaken; to reduce in strength
  Quotations
  wine of it owne nature will not congeale and freeze, onely it will loose the strength, and become appalled in extremitie of cold.
  1601, C[aius] Plinius Secundus [i.e., Pliny the Elder], “(please specify |book=I to XXXVII)”, in Philemon Holland, transl., The Historie of the World. Commonly Called, The Naturall Historie of C. Plinius Secundus. […], (please specify |tome=1 or 2), London: […] Adam Islip, published 1635
4. (intransitive, obsolete) To grow faint; to become weak; to become dismayed or discouraged.
5. (intransitive, obsolete) To lose flavour or become stale.