One of the mysteries of the English language finally explained.
In relation to petrochemistry; by a petrochemical process or method.
In relation to the chemistry of petroleum; by a petrochemical process or method.
1950s. From petrochemical + -ly<br>1960s; earliest use found in The Economist. From petrochemical + -ly.
In this article we explore how to impress employers with a spot-on CV.