aggravate /ˈæɡrəveɪt/ v.

1. If something aggravates a situation, it makes it worse.
2. If someone aggravates you, they make you feel annoyed or angry.

Antarctic /æntˈɑːktɪk/

adj.

Antarctic means in or relating to the area around the South Pole.

n.

The Antarctic is the area of land and sea around the South Pole.

arctic /ˈɑːktɪk/ adj. n.

adj.

Arctic means in or relating to the area around the North Pole.

n.

The Arctic is the area of land and sea around the North Pole.

axis /ˈæksɪs/ n.

1. An axis is an imaginary line through the middle of something.
2. An axis is a central or important part of something which other things depend on or are related to.

degrade /dɪˈɡreɪd/ v.

1. If something degrades, it becomes worse in quality or condition.
2. If someone degrades you, they treat you with no respect.

deteriorate /dɪˈtɪəriəreɪt/ v.

1. If something deteriorates, it becomes worse in quality or condition.
2. If someone’s health or condition deteriorates, it becomes worse.

equator /ɪˈkweɪtər/ n.

The equator is an imaginary line around the middle of the Earth, equidistant from the North and South Poles.

erode /ɪˈrəʊd/ v.

1. If something erodes or is eroded by the weather, sea, or wind, it gradually becomes damaged and destroyed.
2. If something erodes, it gradually becomes weaker or less effective.

globe /ɡləʊb/ n.

1. A globe is a round model of the Earth.
2. The globe is used to refer to the Earth.

hemisphere /ˈhemɪsfɪər/ n.

1. A hemisphere is one half of the Earth.
2. A hemisphere is one half of the brain.

polar /ˈpəʊlə/ adj.

1. Polar means relating to the North or South Pole.
2. Polar means relating to one of the opposite ends of a scale or range of values.

pole /pəʊl/ n.

1. A pole is a long, thin, metal or wooden stick.
2. A pole is either of the two points at the opposite ends of a magnet, where the magnetic force is strongest.
3. A pole is either of the two opposite points on the Earth’s surface where the axis of rotation meets the surface.

upgrade /ʌpˈɡreɪd/ v. n.

v.

If you upgrade something, you improve its quality, status, or value.

n.

An upgrade is an improvement that you make to something, for example by adding new parts to it or by giving it a better design.