'Edgewise' definitions:

Definition of 'edgewise'

adverb

With the edge forward or on, by, or toward the edge; "he sawed the board edgeways"; "held it edgewise" [syn: edgeways, edgewise]

adverb

As if by an edge; barely; "I could not get a word in edgewise" [syn: edgewise, edgeways]

From: GCIDE

Edgeways \Edge"ways\, Edgewise \Edge"wise\, adv. With the edge towards anything; in the direction of the edge. [1913 Webster]
to get a word in edgewise to succeed in expressing an opinion in a conversation, in spite of constant speech from another or others; as, he talked incessantly and I couldn't get a word in edgewise.
Note: the form edgeways is now uncommon. [PJC]
Glad to get in a word, as they say, edgeways. --Sir W. Scott. [1913 Webster]