The Collaborative International Dictionary of English v.0.48:

Summarily \Sum"ma*ri*ly\, adv.
   In a summary manner.
   [1913 Webster]

WordNet (r) 3.0 (2006):

summarily
    adv 1: without delay; in a summary manner; "the suspected spy
           was summarily executed"

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "summarily":
   PDQ, abruptly, apace, aphoristically, at once, briefly, brusquely,
   compendiously, concisely, crisply, curtly, decisively, directly,
   economically, expeditiously, forthwith, immediately,
   in brief compass, in no time, instanter, instantly, laconically,
   on the instant, on the spot, peremptorily, pithily, pointedly,
   precipitately, pretty damned quick, promptly, pronto, quickly,
   right away, right off, sententiously, shortly, smartly, sparely,
   speedily, straightaway, straightway, subito, succinctly, suddenly,
   swiftly, synoptically, tersely, with all speed, without delay,
   without further delay, without hesitation, without warning