We have become accustomed to associating the term "holocaust" to the murder millions of Jews and others during the era of Nazi Germany. However, for over two millennia, the word had a different association. It originally referred to the burnt offering prescribed by God through Moses. For this reason, many Jews resent use of the term "holocaust" as a description of of the 20th century murder of European Jews. Many prefer the term "Shoah".
The term holocaust comes from the Septuagint translation of the burnt offering and derives from two words: holos ("whole") and kaustos ("burnt"). This Greek translation corresponds perfectly to the Hebrew terms holah meaning "that which ascends" as in fire or smoke, and kalil meaning "whole" or "entire". Holokautein denoted that the offering was utterly destroyed and consumed, as opposed to thyesthai which denoted a sacrificial victim and a meal consisting of the victim's flesh. This latter kind of sacrifice became associated with the Holy Eucharist. When Saint Jerome translated the Sacred Scriptures into Latin, he preserved the term in Latin and translated the "burnt offering" as holocaustum and it enters English in this form.
For those interested, the Old Testament prescribes several kinds of holocausts. First there were two daily holocausts at the tabernacle, one in the morning and one in the evening. These two holocausts correspond to the Catholic practice of praying Lauds (morning prayer) and Vespers (evening prayer). These holocausts were combined with a wheat offering and a wine offering (typical of the Holy Eucharist). See Ex 29:38-42 and Nm 28:3-8.
Secondly, there was a holocaust appointed for the Sabbath which was a more elaborate version of the daily double holocaust.
Third, there was the monthly New Moon holocaust and those associated with annual feasts of the Passover, Trumpets, Tabernacles, and Atonement.
Lastly, there were personal holocausts prescribed for various liturgical rites, such as the ordination of priests, purification of women, cleansing of lepers, purifying unclean persons, and the completion of a Nazarite vow.