1.  gb(n = noun.substance) sarin - a highly toxic chemical nerve agent that inhibits the activity of cholinesterase;
is a kind of organophosphate nerve agent

2.  gb(n = noun.quantity) gi, gilbert - a unit of magnetomotive force equal to 0.7958 ampere-turns;
is a kind of magnetomotive force unit

3.  gb(n = noun.quantity) gbit, gigabit - a unit of information equal to 1000 megabits or 10^9 (1,000,000,000) bits;
is a kind of computer memory unit
is a part of tb, tbit, terabit
has parts: mb, mbit, megabit

4.  gb(n = noun.quantity) g, gigabyte - a unit of information equal to 1000 megabytes or 10^9 (1,000,000,000) bytes;
is a kind of computer memory unit
is a part of tb, terabyte
has parts: m, mb, megabyte

5.  gb(n = noun.quantity) g, gib, gibibyte, gigabyte - a unit of information equal to 1024 mebibytes or 2^30 (1,073,741,824) bytes;
is a kind of computer memory unit
is a part of tb, tebibyte, terabyte, tib
has parts: m, mb, mebibyte, megabyte, mib

6.  gb(n = noun.location) great britain - an island comprising England and Scotland and Wales;
is a kind of island
is a part of british isles
has parts: scotland, solway firth
has particulars: albion

gb, abbr. Great Britain.