maintenance of constant difference in frequency between two or more connected circuits or components. To record and examine the progress of something.

To defend someone or something from harm or danger.

Having power or authority.

Being as one would expect; being usual or normal. naturally. person having innate talent.

Believing something will probably happen. To believe something is probably going to happen.

establish identity of.

To go round continuously.

arranged in categories. newspaper advertisements. To keep some information secret from the public.

form or version of something that differs in some respect from other forms of same thing or from standard. Things that differs from some things of the same kind.

Company, firm or business. To be about a particular topic.

at recent time.

Theory that living things change over time.

person who is travelling or who often travels. People going from one place to another.

To move from one person to another, as at a party.

Being what was wanted or needed. used to greet someone in polite or friendly way. Friendly greeting to someone who has arrived. To accept or receive something happily and gladly.