BARRING

verb

1. To obstruct the passage of (someone or something).
2. To prohibit.
3. To lock or bolt with a bar.

noun

1. (collective) Bars; an arrangement or pattern of stripes or bars.
2. The act of fitting or closing something with bars.
3. The exclusion of someone; blackballing.

preposition

1. Unless something happens; excepting; in the absence of.