Drayton makes frequent and varied use of the word strain, which appears in different forms more than sixty times in Poly-Olbion, though rarely in any of its familiar senses. Drayton makes the first recorded use of strain as a verb to describe the flowing of a stream, a usage which appears throughout the poem:

As those that view her tract, seemes strangelie to affright:
So, Toovy straineth in; and Plym, that claimes by right
……
And whence calme Tamer trippes, cleere Towridge in that place
Is poured from her spring; and seemes at first to flowe
That way which Tamer straines: but as she great doth growe
Remembreth to fore-see, what Rivalls she should find
To interrupt her course: whose so unsettled mind
Ock comming in perceives, & thus doth her perswade;
(1.226–7, 266–71)

Strain is also used to describe singing, particularly when Drayton’s Muse is narrating a story or a professional musician is playing:

(4.354–6)

(3.369–70)

Whilst the use of strain to describe the flowing of a river appears to be Drayton’s own coinage, it had previously been applied to singing by John Marston. It is possible that the sense is derived from the existing use of strain that described the tightening of the strings of an instrument, a sense which also appears in Poly-Olbion, along with other more common uses of the word to describe struggle.