In folklore, the devil is generally portrayed as being left-handed. If you get out of bed with the left foot first, you will have a bad day. An itchy right palm means that you will receive money but an itchy left palm means you will lose it.
The Greeks and Romans associated evil with the left hand and we still wear wedding rings on that side in orde to fend it off. The right hand is frequently considered "male", while the left is "female".
In Christianity, the right hand gives the blessing and makes the sign of the Cross. The Bible is said to contain more than 100 favourable references to the right hand and 25 unfavourable references to the left. In Islam. the left hand is seen as unclean and, throughout the Middle East, it is customary to eat with the right hand and reserve the left for matters of personal hygiene.
Foreign words meaning "left" have taken on negative meanings in English. Sinister, from Latin, means malevolent, while gauche, from French, means awkward.