Webster’s Revised Unabridged Dictionary · 1913
Endlong
End′long′, adv. & prep. [Cf. Along.] Lengthwise; along. [Archaic]
The doors were all of adamants eterne, I-clenched overthwart and endelong With iron tough. Chaucer.
He pricketh endelong the large space. Chaucer.
To thrust the raft endlong across the moat. Sir W. Scott.