'Ubiquitous' means present everywhere or widespread, making 'widespread' the closest synonym in meaning.

'Flower' is a homophone for 'flour', sounding the same but having different meanings.

'Happiness' is a noun, while the others are not.

'Under' is the preposition in the sentence.

'Under' is the preposition that shows the relationship between the cat and the table.

'Benevolent' refers to being kind and well-meaning. Hence, the synonym is 'kind'.

'Candid' means truthful and straightforward; thus, it is synonymous with 'honest'.

'Challenging' is a synonym for 'difficult', indicating something that requires effort to overcome.

'Diligent' means having or showing care and conscientiousness in one's work or duties.

'Frugal' means sparing or economical with regard to money or food.

'Hasty' means done with excessive speed; quick.

'Meticulous' means showing great attention to detail, which is synonymous with 'thorough'.

'Guide' is a synonym for 'navigate'.

'Vigilant' means keeping careful watch for possible danger or difficulties.

'Vivid' means producing powerful feelings or strong, clear images in the mind, which is synonymous with 'bright'.

'Ephemeral' means lasting for a very short time, similar to 'transitory'.

'Seperate' is spelled incorrectly; the correct spelling is 'separate'.

'Elated' means very happy or proud; therefore, the synonym is 'joyful'.

'Meticulous' means showing great attention to detail, making 'thorough' the correct synonym.

'Descend' means to go down, which is the opposite of 'ascend'.

'Simple' is the antonym of 'difficult', indicating ease.

'Contract' means to become smaller, which is the opposite of 'expand'.

'Rare' is the antonym of 'frequent', indicating something that does not happen often.

'Selfish' is the antonym of 'generous', indicating a lack of willingness to share.

'Heavy' is the opposite of 'light'.

'Quiet' is the antonym of 'noisy', meaning making little or no sound.

'Pessimistic' is the antonym of 'optimistic', which refers to a tendency to see the worst aspect of things.

'Complicated' is the opposite of 'simple'.

'Failure' is the opposite of 'success', indicating a lack of achievement.

'Car' is not an animal, while the others are all pets.