What is the meaning of: "O Allah, soothe our terrors," and what are these terrors?

The supplication mentioned was reported in a weak hadith in Musnad Ahmad, in which the Companions asked the Prophet, peace and blessings be upon him, for a supplication to say on the day of Al-Khandaq (the Battle of the Trench). He commanded them to say: "O Allah, conceal our faults and calm our fears." The meaning of "calm our fears" is: grant us security from terror. A weak hadith can be acted upon in matters concerning the virtues of deeds.