Gnomish
rag-
verb. to break asunder, burst
i·fesc ar i·dusc
a red rag to a bull, (i.e.) the irritating to the irritable
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A verb appearing as G. rag- “break asunder, burst” in the Gnomish Lexicon of the 1910s (GL/64), perhaps based on the early root ᴱ√RAKA “pile up”, though the meaning doesn’t match (QL/78).
Neo-Sindarin: The Quenya verb Q. rac- “to break” appears in Tolkien’s writings of the 1960s (MC/223), so I think this Gnomish verb can be salvaged as ᴺS. rag- “to break (asunder), burst”. For example, Fiona Jallings used rag- for “break” in her A Fan’s Guide to Neo-Sindarin (FGNS).