To feel curious about something.

A letter of recommendation, e.g. for a job. To cite a piece of research in speech or writing.

For a reason.

band of colours, as seen in rainbow, produced by separation of components of light. The wavelengths of colors from red to violet.

picture or diagram made with pencil, pen. To get closer to or approach something or someone. To take one thing out of a container, etc..

having become yellow. To turn yellow, often due to aging.

used for emphasis with following adjective functioning as adverb. Thing that is not yet known or named.

in way that is not habitual or common.

careful use of resource.

matter. Substances from which a thing is made.

constituting or presenting problem. thing that constitutes problem.

person who is studying or has expert knowledge of one or more of natural or physical sciences. People who are trained in a science.

Having the ability to be glued to something. substance used for sticking objects or materials together.

Hiding your true character to mislead. cover the face.

body's relative mass or quantity of matter contained by it, giving rise to downward force. Heavy metal objects that are lifted for exercise. hold something down by placing heavy object on top of it.