To pound the pavement; used as a verb

Context #1

Leo: How's the job hunting going?

Janice: Not so great. I've been pounding the pavement all week, I've emailed out over 40 resumes, and I still haven't gotten an interview!

Leo: Sorry to hear that. But you'll find something.

Janice: I know. That's why I'm on my way to pound the pavement some more.

Leo: That's the spirit! Keep it up!

Meaning: The expression "to pound the pavement" means to walk through the streets looking for something, usually a job. But while the idiom means to walk through the streets, it doesn't always mean that someone is literally walking around; in the example above, Janice says she has sent over 40 resumes over email, suggesting she isn't literally walking around.  Less commonly, the expression can be used for non-job related activities, although in these cases, it usually means they literally walked around, as in the next example:

Context #2

The candidate's volunteers pounded the pavement, trying to reach out to their community. Due to their efforts, 1000 people joined the candidate's rally the following Saturday.

Meaning: In this example, the volunteers probably did literally walk through the streets, discussing their preferred political candidate with others.

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By the skin of (one's) teeth; used as an adverb

Context #1

Laurie: Hey Alfonso! Wait, why are you all sweaty?

Alfonso: I almost missed the bus.

Laurie: What? You're always on time!

Alfonso: Normally, but I forgot to change my clocks after the time change and only realized when I looked at my phone, which updated automatically. I ran to the bus stop, and it was already there, and I barely caught it by the skin of my teeth.

Laurie: Good thing! This bus only runs once an hour!

Meaning: The expression "by the skin of (one's) teeth" means "just barely". This idiom is used when something was extremely close, as in the above example, where Alfonso nearly missed the bus.  In addition to just barely doing something on time, "by the skin of (one's) teeth" can also be used to show how close a competition was, as in the next example:

Context #2

Beatriz: Did you watch the basketball game last night?

Drew: Yeah. I'm so glad our team won, but that finale was intense!

Beatriz: I know! It really came down to the final seconds, but they pulled it off by the skin of their teeth.

Drew: That last shot was amazing!

Meaning: In this example, the basketball team that Beatriz and Drew were rooting for won a game, but in an extremely close match.

                                          

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