Select the option that gives the most appropriate meaning of the underlined idiom.

The new electrician is a green horn, but will learn fast.

Inexperienced

The most appropriate meaning of the underlined idiom "green horn" is Inexperienced.

The idiom "green horn" is used to describe someone who is new to a particular activity or role, and who does not have a lot of experience. It can also be used to describe someone who is naive or gullible.

In the sentence "The new electrician is a green horn, but will learn fast," the speaker is saying that the electrician is new to the job and does not have a lot of experience. However, the speaker is also saying that the electrician is eager to learn and will likely become proficient at their job with time.

The other options for the meaning of the idiom "green horn" are not as appropriate.

• Efficient means being able to do something quickly and well.
• Proficient means having a high level of skill or knowledge in a particular area.
• Professional means having or showing a high standard of skill and competence.