An Irish saying for being taken by surprise/caught out/an unforeseen event/unpleasant circumstance etc. Many things could lurk in long grass, such as 'shnækes' and other slithery adversaries, to whom one might owe money for instance.

The grass is long, you can't really see what's about you and hence it makes for a prime ambush spot. Visualise strolling through a meadow and all of a sudden being leapt upon by a prowler in the undergrowth. Rarely used in reference to an actual meadow...moreso as a highly amusing colloquialism when rendered in the local accent.
"Seamus owes me €1000, the fecker. Don't ye worry lads, I'll catch'im in the long grass yet!"

"Mick was caught in the long grass by his dealer for late payment"

Waking up with an unknown, unattractive female would count as having caught oneself in the long grass!
by EI6GXB February 2, 2010
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A slang word referring to money
yo dude i ain't have a enough long grass to go out there
by AyMan Dny August 6, 2020
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