Answer:
To 'sequester" a jury means that they are under guard by Court Bailiffs or Sheriff's Deputies 24 hours a day and not allowed un-monitored contact with any outside sources, and who's access to radios, phones, tv, etc. is restricted or denied. A sequestered jury is a situation that is not really all that common, but does occur from time-to-time. It occurs usually only in very 'high profile' cases in which the chances for a mis-trial and/or jury tampering is great. If you are a member of the jury pool that is being considered for such a jury, before you are picked, you will probably be very closely questioned as to your ability to participate in the process.