厄介 [やっかい] – trouble; burden; bother

• 厄 [ヤク] – bad luck; misfortune; disaster
• 介 [カイ] – concern oneself with

You’ll notice by looking at the pronunciation, you’d expect this word to be pronounced やくかい.  However, allowing a く to lead right into a か isn’t considered euphonic.  To fix this, the Japanese will often omit the first syllable and replace it with a small っ, which indicates that the next consonant sound should be doubled.  Thus, やくかい is rendered thus: やっかい.  This happens in many other cases where the first syllable is く or ち:

• 一回 one time:  いち+かい = いっかい
• 各国 all countries:  かく+こく = かっこく

匿名 [とくめい] – anonymity; pseudonym

• 匿 [トク・かくまう] – hide; shelter
• 名 [メイ・な] – name

If you hide your name, you’re anonymous.

祟り [たたり] – a curse

相応しい [ふさわしい] – appropriate

• 相 [ソウ・あい] – mutual; together
• 応 [オウ・あたる] – apply; answer
• しい – adjectival ending

Something that mutually-applies is “appropriate.”  If something is inappropriate, you can express that by changing しい to しくない (e.g. 相応しくない).  If you want to turn it into an adverb, change しい to しく, and affix a verb.

支度 [したく] – preparation; arrangements

• 支 [シ・ささえる] – support; sustain; branch
• 度 [ド・タク] – degree; occurrence; time

New students of Japanese may confuse this word (audibly, not in writing) with したく(ない) – to (not) want to do (something).  They sound identical, so care must be taken to listen to everything in context.

仰天 [ぎょうてん] – to be amazed, horrified, taken aback

• 仰 [ギョウ・あおぐ] – face-up; looking up
• 天 [テン・あめ・あま] – heavens; sky

Imagine being so amazed that you’re lying face-up, looking at the sky.

不覚 [ふかく] – failure; mistake; blunder; negligence

• 不 [フ] – negative; non-
• 覚 [カク・おぼえる] – memorize; learn; remember

Be careful you don’t confuse this with 深く, also pronounced ふかく.  深く means “deeply.”

頭がキーン – Brain freeze; ice cream headache (lit: one’s head goes “squeal”)

カキ氷やアイスクリームを沢山食べると頭がキーンとするのは何故ですか？  Why do I get brain freeze when I eat a lot of shaved ice or ice cream?