A Spießer (also spelled Spiesser when umlauts aren't used) is a German term that describes someone who is conventional, narrow-minded, overly concerned with rules, appearances, and social respectability. It can be humorous or insulting, depending on the context.

The closest English equivalents are:

• a square (rather old-fashioned, but common)

• a conformist

• a stick-in-the-mud

• a stuffed shirt

• a prude (if the emphasis is on morals or sexuality)

• a petty bourgeois person (more literal, but uncommon in everyday English)

Examples

• He's such a Spießer. He worries about what the neighbours think.
  (Er ist so ein Spießer. Er macht sich ständig Sorgen darüber, was die Nachbarn denken.)

• My parents are a bit Spießer when it comes to tattoos.
  (Meine Eltern sind beim Thema Tattoos etwas spießig.)

• I don't want to be a Spießer, but could you keep the noise down after ten?
  (Ich will ja kein Spießer sein, aber könntet ihr nach zehn etwas leiser sein?)

Typical characteristics of a "Spießer"

Someone might be described as a Spießer if they:

• always follow the rules without questioning them,

• care excessively about order and tidiness,

• are very concerned about what other people think,

• dislike anything unconventional,

• value security and routine over adventure,

• complain about small disturbances (e.g. noisy neighbours, grass that's too long).

History

Originally, Spießer referred to medieval townspeople who carried a spear (Spieß). Later it became a term for the lower middle class (petit bourgeois) and eventually developed its modern meaning of someone who is overly conventional and conservative in everyday life.

Modern usage

Today, Germans often use spießig (the adjective) jokingly about themselves:

• I'm getting really spießig these days—I actually enjoy gardening.
  (Ich werde langsam richtig spießig – ich mache inzwischen sogar gern Gartenarbeit.)

• That's a bit spießig.
  (Das ist ein bisschen spießig.)

Interestingly, many people who once rejected "Spießer" values find themselves embracing some of them later in life—buying a house, enjoying gardening, preferring quiet evenings, or worrying about recycling. Germans often joke about "becoming a Spießer" as they get older.

So, Spießer doesn't necessarily mean someone is a bad person. It usually suggests they are overly conventional, predictable, and concerned with respectability, often at the expense of openness or spontaneity.