si SI cmavo

erase the last Lojban word, treating non-Lojban text as a single word.

On gloss:

jvisrbipmo in sense "(Le Système international d'unités; International System of Units) Bureau international des poids et mesures"
x1 is the BIPM (French: Bureau international des poids et mesures; English: International Bureau of Weights and Measures) designation/result/standard/code for topic x2 applied to specific case/individual/group/entity/idea/thing x3 according to rule/BIPM specification x4 published by/according to mandating organization x5 (default: BIPM)
sornai zei raurci'e in sense "International System of Units"
x1 is the SI (International System of Units), defining units x2
zo si si zei fa'o in sense "lojban cmavo"
x1 is a nonsense zei-lujvo using parts x2, silly by standard x3.

In definition:

x1 is silicon (Si)
x1 is the SI (International System of Units), defining units x2
erases a SI, SA or SU cmavo; is to "redo" as SI/SA/SU is to "undo".
x1 is the selma'o "SI".
x1 is an electric charge which measures x2 (li; default: 1) coulombs by standard/under convention x3 (default: SI definition, except the charge of the proton is negative).

In notes:

x1 is an eraser word
x1 is a (unit consisting of) x2 (li; number) of x3 in dimension/aspect x4 (default units)
x1 is 1 [1×100] of x2 in dimension/aspect x3 (default is units).
Copy and paste the overall seltau of immediately preceding sumti at this location.
x1 (collection, body, set, mass, tuple, n-some, etc.) is x2 (li; default: 1) indivisible/atomic/elementary/basic discrete entities (or particles) of type x3 in composition/content, by standard x4; the count of instances of x3 in x1 is x2 by standard x4.
x1 measures to be x2 [li; number] Joule-seconds by standard x3
x1 measures to be x2 [li; number] kilogram-meters-per-second by standard x3
x1 is a part of Lojban text representing rule 'null'
x1 is the elementary unit (quantum) of angular momentum/half of Planck's reduced constant [id est: hbar/2 = h/(4 pi)] expressed in units x2 (default: unitless/dimensionless and so that it is equal to 1) in paradigm/system/metaphysics/universe x3 (default: this, our actual, physical universe)
x1 is \sqrt(A) [decimal: 1×10+(1/2)] of x2 in dimension/aspect x3 (default is units).