From The Collaborative International Dictionary of English v.0.48 [gcide]:
Espial \Es*pi"al\, n. [OE. & Norm. F. espiaille. See Espy.]
1. The act of espying; notice; discovery.
[1913 Webster]
Screened from espial by the jutting cape. --Byron.
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2. One who espies; a spy; a scout. [Obs.] "Their espials . .
. brought word." --Holland.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
espial
n 1: the act of detecting something; catching sight of something
[syn: detection, catching, espial, spying,
spotting]